A pulse width modulator is a main device for an electric power conversion system, and based on a pulse width modulation (PWM) for effectively controlling conversion between DC power and an AC power.
A general energy transferring means includes a PWM converter, a switching electric power terminal, a filter and a controller. The general energy transferring means has problems of limiting a design of a system, making complex of the design, and a difficulty in designing a stable system.
In order to solve the above problems, the pulse width modulator becomes effective in embodying a system, stable and simplified through feedback (low pass filter or feedback block) of output signal of each power terminal in recent years.
However, according to the conventional technology, a signal loop is formed in a single loop to independently operate, and a synch block is used for a differential amplification, so that there in a limit in generating a differential PWM signal outputted to a load.